Fourth Army
- 20th Guards Army
- 4th Air Army
- 4th Army (Austria-Hungary)
- 4th Army (German Empire)
- 4th Army (Kingdom of Yugoslavia)
- 4th Army (RSFSR)
- 4th Army (Russian Empire)
- 4th Army (Soviet Union)
- 4th Army (Wehrmacht)
- 4th Brigade (disambiguation)
- 4th Division (disambiguation)
- 4th Guards Army
- 4th Panzer Army
- 4th Regiment (disambiguation)
- 4th Squadron (disambiguation)
- Fourth Army (Bulgaria)
- Fourth Army (France)
- Fourth Army (Italy)
- Fourth Army (Japan)
- Fourth Army (National Revolutionary Army)
- Fourth Army (Ottoman Empire)
- Fourth Army (Romania)
- Fourth Army (United Kingdom)
- Fourth United States Army
- IV Corps (disambiguation)
- New Fourth Army